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List Of Hyolith Genera
This list of hyoliths is an attempt to create a comprehensive listing of all Genus, genera from the fossil record that have ever been considered to be members of hyolitha, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomen dubium, nomina dubia''), or were not formally published (''nomen nudum, nomina nuda''), as well as synonym (zoology), junior synonyms of more established names, and genera that are no longer considered hyoliths. Naming conventions and terminology Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Synonym (zoology), Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type (zoology), type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synonym, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplophrentis
''Haplophrentis'' is a genus of tiny shelled hyolithid which lived in the Cambrian Period. Its shell was long and conical, with the open end protected by an operculum, from which two fleshy arms called ''helens'' protruded at the sides. These arms served to elevate the opening of the shells above the sea floor, acting like stilts. Morphology Shell length of ''H. reesi'' reached up to while ''H. carinatus'' reached up to . Juveniles could of course be smaller. It is distinguished from '' Hyolithes'' by the presence of a longitudinal septum on the middle of the inner surface of the top of the shell. Its soft anatomy comprises 12 (''H. carinatus'') to 16 (''H. reesi'') tentacles attached to a horseshoe-shaped lophophore. A pair of wide structures of uncertain function extend along the length of the conical shell. A larval shell is attached to the shell apex. Affinity The soft anatomy of ''Haplophrentis'' was key to establishing the hyoliths as members of the Lophophorata, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
